leetcode

Daily Problem

2 files changed, 31 insertions(+), 0 deletions(-)

diff --git a/ Problems/0840.cpp b/ Problems/0840.cpp

@@ -0,0 +1,30 @@

class Solution {

public:

int numMagicSquaresInside(const vector<vector<int>> &grid) const {

const int n = size(grid), m = size(grid[0]);

int res = 0;

for (int i = 1; i < n - 1; i++) {

for (int j = 1; j < m - 1; j++) {

if (grid[i][j] != 5) continue;

if (grid[i - 1][j - 1] + grid[i - 1][j] + grid[i - 1][j + 1] != 15) continue;

if (grid[i - 1][j - 1] + grid[i][j - 1] + grid[i + 1][j - 1] != 15) continue;

unordered_set<int> us;

for (int k = i - 1; k <= i + 1; k++) {

for (int l = j - 1; l <= j + 1; l++) {

if (grid[k][l] < 1 || grid[k][l] > 9) goto next;

if (us.count(grid[k][l])) goto next;

us.insert(grid[k][l]);

}

}

res++;

next:;

}

}

return res;

}

};

diff --git a/ README.md b/ README.md

@@ -525,6 +525,7 @@ for solving problems. | 0837 | Medium | [New 21 Game](Problems/0837.cpp) | | 0838 | Medium | [Push Dominoes](Problems/0838.cpp) | | 0839 | Hard | [Similar String Groups](Problems/0839.cpp) |

| 0840 | Medium | [Magic Squares In Grid](Problems/0840.cpp) |

| 0841 | Medium | [Keys and Rooms](Problems/0841.cpp) | | 0844 | Easy | [Backspace String Compare](Problems/0844.cpp) | | 0846 | Medium | [Hand of Straights](Problems/0846.cpp) |